Animal Diversity and Phylogeny

Flashcards to help review key concepts related to animal diversity and phylogeny from the lecture notes.

What are the four ecological questions to address for each organism in Unit II?

1. How does it move? 2. How does it interact with its (a)biotic environment? 3. How does it obtain energy? 4. How does it reproduce?

Define synapomorphy in the context of animal classification.

A synapomorphy is a derived trait that is shared by a group of organisms and is used to determine their phylogenetic relationships.

What is the key distinguishing synapomorphy of the Phylum Chordata?

Notochord, dorsal hollow nerve chord, post-anal tail, and pharyngeal gill slits.

What is the difference between monophyletic, paraphyletic, and polyphyletic groups?

Monophyletic groups include an ancestor and all its descendants; paraphyletic groups include an ancestor but not all its descendants; polyphyletic groups include organisms from different ancestors.

What are plesiomorphies and how do they differ from synapomorphies?

Plesiomorphies are ancestral traits that are shared among species, while synapomorphies are derived traits that are unique to a specific group.

Identify two examples of unique distinguishing synapomorphies in Mammalia.

Lactation and four-chambered heart.

What evolutionary concept is illustrated by traits that evolve independently in different lineages?

Convergent evolution.

What type of taxonomic characteristics organize bilateral taxa into monophyletic groups?

Presence or absence of (pseudo)coelom.

Define exaptation in evolutionary biology.

Exaptation refers to a trait that originally evolved for one function and was later co-opted for a different function.

What classification levels are used in the traditional system of animal classification?

Kingdom, Phylum, Class, Order, Family, Genus, Species.

Which phylum is considered the most ancestral in the animal phylogeny?

Porifera.

What does the term 'triploblastic' refer to in animal development?

It refers to organisms that develop from three germ layers: ectoderm, mesoderm, and endoderm.

What synapomorphy is characteristic of Echinodermata?

Radial symmetry and a water vascular system.

How do traditional and newer phylogenies differ in their construction?

Traditional phylogenies rely mainly on morphological data, while newer phylogenies are constructed using molecular data.